There are several situations wherein a patient suffers from a condition that renders it difficult, unsafe or impossible, either temporarily or permanently, to take food through their mouth. In such situations it is known to use a tube to feed the patient. This process is referred to as gavage, internal feeding or tube feeding. Essentially, tube is placed so that one end thereof is disposed in the stomach of the patient and fluids containing food and/or medicine are pumped into the stomach from the other end of the tube. A variety of feeding tubes are used in medical practice, as required by the condition of the patient.
The placement of the tube may be temporary or life-long depending on the condition of the patient and a number of alternative methods can be employed. For relatively short term one end of a nasogastric feeding tube may be inserted through the nasal cavity and fed down the oesophagus and into the stomach. Patients requiring longer term therapy may be provided with a more permanent solution such as a percutaneous endoscopic gastrostomy (PEG) which is passed into the stomach of the patient through their abdominal wall.
It is widely accepted as essential practice that medical staff should confirm that one end thereof is disposed in the stomach before fluids are administered via the tube. This is essential because between feeds movement of the patient can result in migration of the end of the feeding tube. For example, the end of the feeding tube may migrate to the oesophagus of lungs. Administration of fluids into the lungs could result in serious harm to the patient and could even be fatal.
There are three known methods for verifying the position of the end of the feeding tube that are practiced to date.
The first method involves connecting a syringe to a first end of the feeding tube and drawing up a sample of fluid therefrom. The syringe is removed from the feeding tube and the acidity of fluid is tested using pH indicator strips or paper. If the acidity of the fluid matches that of gastric juices then it is assumed that the other, second end of the feeding tube is disposed in the stomach and the medical staff can safely administer fluid via the feeding tube. This method requires at least two connections to be made to the feeding tube per feed, each connection carrying a risk of contaminating the feeding tube. It requires several steps to be followed by the medical staff, can be time consuming and could lead to the medical staff sustaining a repetitive strain injury. Furthermore, whilst using this method there is a risk that medical staff may be exposed to bodily fluids of the patient.
A second method relies upon the use of an X-ray to confirm the position of an end of the feeding tube. This method is rather expensive and relies upon bulky inconvenient apparatus. Furthermore, this method poses additional health risks, such as an increased risk of developing cancers, to the patient and medical staff, especially if used frequently and/or over a prolonged period of time.
A third known method is known as auscultation. This involves connecting a syringe to a first end of the feeding tube, injecting air into the feeding tube and listening, using a stethoscope, for the sound of bubbling at the other, second end. If bubbling is identified then it is assumed that the other, second end of the feeding tube is disposed in the stomach and the medical staff can safely administer fluid via the feeding tube. This involves a significant degree of skill and it therefore unsuitable for use by inexperienced or untrained medical staff. There is also greater scope for human error to result in a misidentification of the position of the second end of the feeding tube than with the other two methods.
It is an object of embodiments of the present invention to at least partially overcome or alleviate the above problems.